Field of the Invention
The present invention relates to a fuel cell system and a fuel consumption system. In such a fuel cell system, e.g., a fuel cell vehicle, or such a fuel consumption system, e.g., a hydrogen engine vehicle or a CNG (Compressed Natural Gas) vehicle, a fuel storage unit such as a gas tank or the like disposed in the system is filled with a fuel gas from an external fuel gas supply apparatus such as a gas station or the like for storing the fuel gas in the fuel storage unit, and thereafter the fuel gas stored in the fuel storage unit is consumed, by way of reaction or combustion, in order to generate and utilize energy.
Description of the Related Art
Fuel cells such as solid polymer electrolyte fuel cells operate in the following manner. A fuel gas, such as a hydrogen-containing gas, which is supplied to an anode electrode, is ionized by an electrode catalyst into hydrogen ions. The hydrogen ions then move through an appropriately humidified electrolyte membrane to a cathode electrode. Electrons, which are generated while the hydrogen ions move from the anode electrode to the cathode electrode, are supplied to an external circuit, which makes use of the electrons as DC electric energy. Since the cathode electrode is supplied with an oxygen-containing gas such as air, the cathode electrode allows the hydrogen ions, the electrons, and the oxygen to react with each other, thereby producing water.
Fuel cell vehicles have been proposed, which are propelled by an electric motor energized by an energy source including electric energy generated by a fuel cell and electric energy stored in an electric energy storage device.
Hydrogen engine vehicles and CNG vehicles have also been proposed, which are propelled by an engine which operates in such a manner that a fuel gas is injected into the engine and combusted in order to rotate a crankshaft. Rotational energy of the crankshaft is shifted in speed through a transmission, and transmitted to enable the vehicles to travel.
Fuel cell systems such as fuel cell vehicles or the like and fuel consumption systems such as hydrogen engine vehicles or the like preferably include a fuel storage unit such as a gas tank or the like, which can be filled up completely with a fuel gas in a single fuel filling process.
Japanese Laid-Open Patent Publication No. 2011-033068 (hereinafter referred to as “JP2011-033068A”) discloses a gas filling system. The disclosed gas filling system operates in the following manner. When a fuel gas supply apparatus supplies a fuel gas to fill a system-side fuel storage unit, a system-side filling control unit, also referred to as a filling ECU (Electronic Control Unit), sends information concerning characteristics of the fuel storage unit as well as the temperature and pressure in the fuel storage unit through a system-side communication unit to the fuel gas supply apparatus via an infrared communications link. Such information is sent at the time that the fuel gas starts to fill the fuel storage unit, as well as while the fuel gas is filling the fuel storage unit, i.e., during the fuel gas filling process.
The fuel gas supply apparatus receives the information concerning the characteristics of the fuel storage unit as well as the temperature and pressure in the fuel storage unit, determines a filling rate, etc., based on the received information, and continues to fill the fuel storage unit with the fuel gas.
If the filling ECU detects that a filling failure has occurred, e.g., if the temperature in the system-side fuel storage unit is unduly high, then the fuel gas supply apparatus, which has received information concerning the detected temperature, etc., performs a control process in order to lower the filling rate based on the received information, and then continues to fill the fuel storage unit while the temperature in the fuel storage unit is prevented from increasing further (see paragraphs [0012], [0015], [0017], and [0025] of JP2011-033068A).